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atmospheric chemistry Articles

Here, only some data can be modified. The necessary data is: Pollutant emission rate (g/m s): This is the pollutant emission rate. Decay coefficient (1/s): This coefficient considers the half life of the pollutant if this ...

Historically some of the new EU Member States and the Candidate countries experienced high levels of pollution in the past. Enhanced management measures were and are needed to improve the air quality. The present survey on the ongoing air chemistry research is in support to such measures and the incorporation of the EU environmental legislation in the air quality management of these countries. ...

Issue Combustion efficiency is a measurement of how well any given fuel is being burned and converted into useful energy (e.g.: heat, hot water, steam). The calculations are based on 3 MAJOR Factors: Chemistry of the burned Fuel (e.g. Propane, Natural Gas, Oil, etc) The CO2 percentage by volume after the combustion ...

pH measurement in high purity water has met with variable success. The high resistivity of pure water, the vulnerability to contamination, the variability of reference electrodes and additional temperature effects converge to make tins a particularly challenging measurement. Overcoming these obstacles requires a thorough understanding of the potential problems and their systematic solution. ...

This study provides a comprehensive report on mass concentrations, chemical composition and mineralogy characterisations of PM10 atmospheric aerosols in the Gulf of Gabès, in South Tunisia. Data were collected at 18 locations (sample points in urban zones with industrial influence). Principally, they were located near the industrial complex. At each sample point, PM ...

The growing trend of industrialization has marked impact on the atmospheric chemistry around the globe. Such impacts are also predicted for developing countries like India. Acid precipitation due to secondary pollutants is one of them. The present investigation was conducted with an aim of studying the precipitation chemistry over Asansol city, India during the monsoon season. The rain water ...

Technical toxaphene (TT), a broad‐spectrum pesticide mixture, degrades in the environment, resulting in potential changes in toxicity. The present study uses a multi‐media model that we developed to estimate toxaphene degradation in the atmosphere over North America. The predicted degradation has strong spatial and temporal variability determined by processes such as emission and transport of ...

In this work, a Lagrangian particle model able to account for simple chemical reactions between NO and O3 has been improved to consider the photolysis of NO2. A system of chemical equations is numerically solved on a Eulerian grid, while the particle trajectories are moved in a Lagrangian frame. The ...

Since the (partial) acceptance in Italy of the EU Directive 85/337/EEC concerning environmental impact assessment procedures, there has been a rapid growth in the use of atmospheric dispersion simulation tools, which are also being used in air-quality management plans. This paper describes the state of the art in the development and application in Italy of the short and medium range ...

In this article, selected weather prediction model parameters, which are important for air pollution studies, were verified against measurements at two sounding stations in Finland. In 1996–1998, the short-time model-measurement differences were rather high. The friction velocity was on average overestimated by 30–70%, the mixing height during spring months was underestimated by up to 60%, 2 m ...

On June 13, 2016, the U.S. Environmental Protection Agency (EPA) announced the winners of the 2016 Presidential Green Chemistry Challenge Awards (PGCCA). The PGCCA honors green chemistry technologies that solve climate and environmental problems through creating business ...

Abstract Air in-leakage into the steam space of a condenser can become stored in pockets of high partial pressures that negatively impact condenser performance and become a source of dissolved gases in the feedwater. These pockets can be configuration caused and generally cannot be eliminated by reducing air ingress or increasing venting capacity. Fortunately, engineering designs are ...

A realistic understanding of contaminant sources is required to set appropriate control policy. Forensic chemical methods can be powerful tools in source characterization and identification, but they require a multiple‐lines‐of‐evidence approach. Atmospheric receptor models, such as EPA's Chemical Mass Balance (CMB), are increasingly being used to evaluate sources of pyrogenic polycyclic ...

The numerical simulation of atmospheric pollution needs long calculation times, mainly due to the chemistry involved, for example in photochemical episodes for which a lot of species and reactions must be taken into account. Parallelisation can reduce these calculation times. In this work, we have made parallel computation with a Eulerian transport/chemical model with the MPI communication ...

Mercury (Hg) is considered a priority pollutant because of its toxicity and potential for strong bioaccumulation.There are many serious environmental and human health concerns associated with elevated levels of Hg linked to industrial ...

Few studies of atmospheric deposition come from the fast growing region of Southeast Asia. Precipitation in Changhua City in central Taiwan was collected to examine its chemical composition and relationship with meteorological patterns. Fifty percent of the precipitation measurements had pH ...

To determine whether NO3−, concentration pulses in surface water in early spring snowmelt discharge are due to atmospheric NO3−,, we analyzed stream δ,15N-NO3−, and δ,18O-NO3−, values between February and June of 2001 and 2002 and compared them to those of throughfall, bulk precipitation, snow, and groundwater. Stream total Al, DOC and Si concentrations were used ...

Computational fluid dynamic (CFD) modelling of pollution dispersion and chemical conversion to aerosol particles in the atmospheric boundary layer (ABL) has been studied. The investigation focused on the numerical modelling above complex orographic terrains of urban areas and industrial sites including the dispersion of toxic substances in the air as a result of accidents. A finite-rate model of ...

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